Method of joining concrete sections and dowel pin covers therefor



E. H. ANGIER Feb. 13, 1934.

METHOD OF JOINING CONCRETE SECTIONS AND DOWEL PIN COVERS THEREFOR Filed April 9, 1952 (all Patented Feb. 13, 1934 NKTE s'rArss I METHOD OF .IOINING CONCRETE SECTIONS AND DOWEL PIN COVERS THEREFOR EdwardH. Angler, Framingham, Mass.

Application April 9, 1932. Serial No. 604,231

2 Claims.

My present invention relates to an improved and novel method or" concrete construction where dowel pins are utilized, and to a novel method of protecting and spacing both the length and the ends of dowels from contact with the concrete to allow for free play or relative move ment during contraction and setting of the concrete, or of the expansion and contraction of the dowel.

In the present methods of laying a plurality of sections of concrete, whether in walls, floors, or roadways, and particularly in constructing road surfaces, it is customary and necessary to appl at various points metal dowels, which are embedded in the first layer of concrete at a plurality of points, either longitudinally or endwise, such dowels having a substantial portion projecting to interlock with the next adjacer' section of concrete. Before applying the adjacent layer, and to allow for a proper clearance or space around and beyond the end of a dowel, I apply my novel cover to the projecting portion of the dowel, which will prevent the concrete from contact with the dowel throughout its length, giving a space or clearance, also with the end of the dowel, and thus to allow for the give-and-take when contraction takes place of the new concrete section, or of the metal dowel itself.

Heretofore, it has been customary to use paper tubes of preformed tubular paper, cardboard, or the like, which will slip on the end of the projecting portion of the dowel and be of sufiicient diameter to preserve an open space therearound.

This former practice has been objectionable in that these covers or tubes are bulky, require considerable space for storage and transportation, permit excessive waste because of breakage, and, furthermore, are subjected to disintegration and collapsing when wet, often breaking and failing to preserve the space necessary and desired for the subsequent contraction and setting. As such work is outdoors and in all weathers, and as the concrete is poured when wet and moist, the difficulty of use with such prior paper tubes has been a serious matter. Also, such prior tubes had to be applied just before the adjacent section was poured, and thence this work could not be done at convenient times. In my present invention I have obviated the difficulties above briefly outlined and have improved the operation of interlocking concrete sections with dowels, insuring uniformity in space to allow for the shrinkage, and preventing distortion and damage to the dowels, and consequently improving the entire concrete structure when made from a plurality different pourings.

I accomplish the desirable result above briefly outlined by providing a waterproof cover for the dowels, which preferably also may be collapsible to conserve space in transportation and storage and can be readily withdrawn from such package, opened on the job, and applied to' the dowels. Furthermore, being waterproof, they will maintain their position and serviceability for days at a time, even during rain, andovernight, and in moisture without damage-or distortion, permitting application at any time convenient without regard to the next laying of an adjacent concrete section.

I may also provide such waterproof dowel covers with a metal wire or. pin, which would facilitate positioning and holding of the outer exposed end of the dowel.

As shown in the drawing, my improvement in concrete structure, dowels, and caps therefore in preferred form are illustrated.

Fig. 1 is a diagrammatic plan view embodying the invention. 8 Fig. 2 illustrates, partly in cross-section and on an enlarged scale, the process of applying and holding a waterproof cover, and my novel metal cap.

Fig. 3 is an end view looking from the right 8 of Fig. 2.

Fig. 4 is a perspective of a collapsed tube cover.

Fig. 5 is a perspective view of the metal end 9 p;

Fig. 6 is a view, partly in cross-section, of the use of a waterproof cover and holding wire bent into position without the cap, and

Fig. 7 illustrates a modified form, wherein the dowel cover has a reinforcing or stiffening beyond the end of the dowel pin.

As shown in Fig. 1 illustrating a concrete road construction, it is customary to pour concrete in parallel lengths and have predetermined sections lengthwise of the structure. These widths 1 may be of any desired amount or extent. Usually one width and section is poured, allowed to set and, thereafter, an adjoining section is poured and set. During the pouring of the first section, shown for example as 1 in the drawings, a dowel pin of metal 2 is fitted at a plurality of places laterally when the adjoining concrete layer is to be poured on its thinner side. Such a section is indicated at 3, Fig. 1. When a longitudinal section is to be poured, as indicrete l which has already been cured, as clearlyshown in Figs. 2 and 6. These covers may be of suitable length for the projecting portionof the dowels 2, or, and preferably, may be provided with a bendable wire 15 fitted in at one end. and capable of being bent at the outer end to constitute a supporting element, as illustrated in- Figs. 2 and 6.

Thus I can utilize a relative simple, thin, waterproof, flexible, and collapsible covering 10, apply the same on the projecting dowel with the supporting ends 12 on the concrete and the wire 15 on the opposite end, and can position and maintain the tube relatively with a dowel 2 with a substantial air space ZOtherearound to provide for the desired amount of spacing for the newly poured concrete section.

As shown in Figs. 2 and 5, I have illustrated a novel metal cap 25 which may be utilized to preserve a spacing at the end of the dowel 2. This cap is provided with a series of slight indentations 26, spaced sufficiently from one end, viz.,. the left, viewed in Figs. 2 and 5, to permit the cap to fit over the outer end of the dowel 2.

. until such portions of the indentations 26 on the inside are in contact with the ends of the dowel, thus constituting a stop. By this arrangement, in case of contraction or expansion of the metal dowel, or the concrete, or both, the slight indentations 26 will not interfere with the expansive action, being simply pushed off or upwardly and thus still preserving a space at the end of. the rod. This cap may be used with or without the cover 10, preferably with the same,

and as clearly shown in Fig. 2.

It will thus be seen that I have provided means for insuring the uniform spacing around both the length and the projecting ends of the dowels. This uniformity is a great improvement of this art and with my arrangement of waterproof covering and, preferably, a supported end, I am enabled to greatly improve any concrete structure utilizing dowels and insure uniform interlocking of successive pourings.

As shown in Fig. 7, I have illustrated a modified form of dowel cover, wherein the conver 30 extending, around the dowel. pin is of sufiicient length: to extend substantially around the end of the dowel to receive a mass of reinforcing packing 31, together with the outermost ends of the;dowel cover, which may be brought together at 32 and secured by staples 33, or the like. In thisform; the dowel cover itself constitutes both the lengthwise or endwise spacing or clearance. for the dowel to provide for contraction and expansion of' both dowel and concrete.

Thus, a mass of compressible material providesa. suitable spacing during the pouring of the concrete to allow for setting of the concrete and expansion or contraction of the dowel, particularly lengthwise at this point, the packing being; readily compressed during such action.

I believe that the use of a dowel cover of waterproof material capable of application at any time irrespective ,of weather conditions, also that such a cover with an end-projecting portion over the. end of the dowel to provide space for same, as well as the provision of such a cover adapted. tobe pressed against the previously set section, either with. or without the supporting means for the free end, as well as the improvement in. the entire process of joining concrete sectionsresulting from the use of my device, is new andI wish. to claim the same herein broadly.

I claim:

1. Asa. new. article of manufacture, a. waterproof coveringfor concrete dowel pins, having a split portion at one end of the cover adapted to be. spread to bear against the face of the concrete section in which the dowel has been embedded, towhichthe cover is applied.

2. A dowel cover of the kind described, comprising a..waterproof dowel encircling portion and. a projecting end portion, and means to hold packingmaterial, in the outerv end of saidcover, and means to enclose and secure said packing therein.

EDWARD I-I. ANGIER. 

